In the first grant we demonstrated that novel low molecular weight (MW) displacers can be successfully employed for high resolution/high throughput protein purifications in ion exchange systems. We have recently demonstrated that low molecular weight displacers can also be used for oligonucleotide purification and that the stationary phase has a significant effect on the efficacy of various low molecular weight displacers. In this phase of the project we will expand this research by addressing several critical issues related to the rational design of efficient low MW displacers. The proposed research will expand our investigation into the relationship between displacer chemistry and its efficacy as a protein displacer. The proposed research will include displacer synthesis, development of high affinity displacers for cation and anion exchange systems, development of efficient selective displacers, and the application of these variants of a variety of low MW displacers identified in the first grant. In addition, this phase of the project will examine the effect of stationary phase chemistry on the efficacy of various classes of low MW displacers using resins with various backbone chemistry, spacer arm chemistry, charged ligands and ligand densities. The efficacy of displacement chromatography for oligonucleotide purifications will be examined in detail. The displacers developed in this research will be employed in a detailed investigation of the interplay between displacer chemistry and displacer affinity on various stationary phase materials. This research will evaluate several hypotheses related to displacer design. The low MW displacers developed in this research will be employed for the purification of proteins and oligonucleotides from complex biological mixtures. Finally, these high affinity displacers will be employed to develop a generic displacement will provide significant insight into the design or efficient low MW displacers for protein and oligonucleotide purification and will enable the purification of a wide range of biopharmaceuticals in a more efficient manner. Furthermore, this work will facilitate the use of this high resolution/high throughput technique by medical researchers at the bench scale for the rapid purification of novel biomolecules form dilute complex mixtures.